Summary of USING A VENDING MACHINE BILL ACCEPTOR WITH ARDUINO
The article explores a bill acceptor removed from an arcade machine, detailing its internal mechanics and how it differentiates real currency from paper. It highlights a project where [Another Maker] reverse-engineers the device and interfaces it with an Arduino, enabling various currency-related experiments. The bill acceptor uses belts and IR LEDs to scan bills, relying on firmware updates to recognize new currency designs. The device examined is outdated, unable to process modern $5 bills, which explains its free acquisition. The article references an earlier use of such devices in a DIY Bitcoin ATM.
Parts used in the Bill Acceptor Arduino Interface Project:
- Bill acceptor unit (vending machine type)
- Arduino microcontroller
- IR LEDs (part of bill acceptor hardware)
- Belts for bill transport (part of bill acceptor hardware)
We have all encountered bill acceptors like the one [Another Maker] recently removed from an arcade machine and sometimes struggled with them. Have you ever disassembled one to observe its functioning? If not, the video following this is an intriguing look at how this common device distinguishes between a genuine bill and a sheet of paper.

But [Another Maker] goes a bit farther than just showing the internals of the device. He also went through the trouble of figuring out how to talk to it with an Arduino, which makes all sorts of money-grabbing projects possible. Even if collecting paper money isn’t your kind of thing, it’s still interesting to see how this gadget works on a hardware and software level.
As mentioned in the video, a collection of belts is utilized to move the bill in front of multiple IR LEDs. The hardware relies on these tools to scan the bill and use some sort of mysterious sorcery to verify if it’s a real piece of currency. [Another Maker] emphasizes that these readers must be updated with firmware periodically to accommodate new bill designs. Indeed, the unit he owns is extremely outdated to the point that it cannot process current $5 bills, possibly clarifying why he received it for no cost initially.
Years ago we saw one of these bill acceptors used to make a DIY Bitcoin ATM. Of course back then, a few bucks would get you a semi-reasonable amount of BTC. These days you would skip the paper currency and do it all digitally.
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